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J

jimmy

It's been a few years since college and I'm stuck on understanding this,

I'm getting an intermittent fault on kitchen sockets. Causing some tripping.

Broken it down and when I IR test the circuit. L to E is 200+
N to E is 200+
But when I test N&L to E thruster fluctuates between 120Mohnm to 160Mohm

I don't understand why it's over 200 M when I test separately.

Can anyone explain to my stupid brain please. TA
 
Assuming both N-E and L-E have an IR of 220Mohm then the combined IR would be much lower:
1/(1/220+1/220)= 110Mohm

This would explain your situation but whether it's the actual cause or not I don't know!
 
a reading of 120 Meg is good enough to be ignored. your fault is more likely to be an appliance.
 
fault on N&L to CPC

Definitely not an appliance. Thanks big cheese that explains the reading. It's now dropping down to 30Mohm now and again.

So how can I trace intermittent faults without rewiring everything?
 
if the circuit is a ring. guesstimate the mid point and split it. then you may well find a low reading on 1 leg. then split that leg again.... and so on till you narrow it down. even so, 30Meg. will not trip a RCD.
 
fault on N&L to CPC

Spent hours doing that. I get 200+ on leg L&N to E then 10mins later back to below 100Mohm.

I'm worried about the fault to other causing problems to the ladies appliances.
 
Have you taken the sockets off the wall? Is anything damp / newly plastered / decorated? How old is the install? 30M should be findable and I personally would look for it because it could direct you to the site of cable damage etc; a short length of T+E and a few fittings should be able to get over 30M. But 100M... a few years ago your tester wouldn't have been able to read that high. I wouldn't exactly call it a fault and it wouldn't cause any other problems.
 
fault on N&L to CPC

Well I've put all sockets back on and it's reading 200M+ L&N combined. Don't know why. Maybe fiddling with sockets?? Who cares I'm walking away now :)
 
Re: fault on N&L to CPC

Well I've put all sockets back on and it's reading 200M+ L&N combined. Don't know why. Maybe fiddling with sockets?? Who cares I'm walking away now :)

That's that one sorted then! Ermmm....... Daz
 
could have been a cable caught up by a screw or squashed against the back box. by pulling the faceplate off and refitting, you could have cleared the fault.
 
Damp maybe a prime suspect on this one, or the old bottle sterilizer right next to socket or kettle etc . U could remove all sockets and connector block the ring and test cable only. Just s thought!
 

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